Yesterday I received the 135mm f/2 and really didn't have a whole lot of time to spend using it but I did come across one scenerio that puzzled me.

I was just taking a few random shots as I was sitting at my computer desk. One of the shots being at one of my dogs orange rubber ball that was on the carpet approx. 12 ft. away or so. The room is not the greatest for lighting. Abovewhere I was sitting, there is a ceiling fan that has three lightbulbs and then farther down the room approx. 10 ft. behind the ball there was a small lamp that was turned on.

To make a long story short, the Canon 135mm could not focus on this ball. The only setting I remember (I'm at work now) was that I had it at f/2. I tried repeatedly to get at least one shot at various shutter speeds and the lens would not focus and I could not get the camera to fire one shot.

I then I put the Sigma 85mm on at set it at f/2 and it focused quickly and I was able to get numerous shots with no problem whatsoever.

Just a quick observation that I found puzzling. I mean isn't that 135mm f/2 suppose to be a fast focusing low light lens? All in all, the light was not even THAT low for it to not be able to even fire a somewhat dark shot at least.

Denise